SIDD will not show one computerr. SIDD is visable on 8 other devices

I have a NetGear Nighthawk RRRAX 40 wicg I have been using for several months ands i t works fine. I bought a small cube computer and it will not see the SIDD network. Have worked hours on but to no avail. This morning I removed the Netgear Night Hawk and installed and old router and the cube comuter saw the SSID and I loged on to the internet with it. I now know thaat the problem is with thr router. Looking for soultion.thanks